There is rarely a good time to do hard things, and America won't advance if legislators act like seat-warmers.

When I learned that House Majority Leader Eric Cantor had lost his Republican primary, my heart sank. Not simply because I think he is an intelligent and talented member of Congress, or because I worry about the future of the Republican Party.

Like others who want comprehensive immigration reform, I worried that Mr. Cantor's loss would be misconstrued and make Congress reluctant to tackle this urgent need. That would be the wrong...